Google in Education

Google for Educators
Educational Technology and Life (Google in Education Category)
See also the GooglEd Wiki

More... Even More

Google More...
Google Labs
Google Help Center

Search Tools: 21st Century Skills

Web Search Support (Don't forget to learn the Google Operators like Define: and others.)
News Search Support
Book Search Support
Scholar Search Support
Blog Search Support
Custom Search Engine Support
Image Search Support
Video Search Support
Map Search Support (Check out Street View in Yosemite Valley!)
Google SMS (Just text a search to 466453)
Google 411

Don't forget Google Translations!

Web-based Applications

Docs and Spreadsheets Support
Calendar Support
Google Page Creator Support
Blogger Support
Reader Support
iGoogle (Google Homepage) Support (See "Personalizing iGoogle")
Google Notebook SupportGmail & Gtalk

Desktop Applications

Earth Support
Sketch Up Support
Desktop Support (Windows Only)
Picasa Support (Windows Only)

Additional Links

Google Hacks - A good reference book. The first half or so includes some great tips... the rest gets a bit technical.
Googlepedia - Another good reference book to use when teaching particular applications.
Google Earth Lessons - A bunch of lesson plans.
Google Lit Trips - By Jerome Berg